Field of the Invention
The invention relates to a biological device and a method for purifying malodorous gas and wastewater, and more particularly to a coupling bioreactor and a method for purifying malodorous gas and wastewater.
Description of the Related Art
Malodorous gas treatment is an important process in environmental pollution control. Two typical methods for treating malodorous gas include a physicochemical method and a biological method. The physicochemical method involves a complicate process and device, high operation cost, but a low efficiency. The biological method has a high efficiency of treatment, wide application, simple process, and low cost, thereby being a main technology in treating malodorous gas.
Typical biological treatments for malodorous gas include biotrickling filtration, biological filtration, bioscrubber, and biological aeration. The biotrickling filtration includes filling an inert filler into a biotrickling filter, that is, a reactor; inoculating microbes and controlling a proper condition for biofilm culturing on the inert filler; covering a surface of the inert filler by the biofilm; and meanwhile continuously spraying nutrient solution necessitated by metabolism of the microbes on the filler by using a circulation system. When the malodorous gas passes through the filler in the coupling bioreactor, pollutants are degraded by microbes. The biotrickling filtration has high load, and is highly controllable, so that it has been the most widely used biological treatment for malodorous gas.
However, problems, such as a large pressure fall, biomass accumulation, and blockage of the filler, exist in actual operation of the biotrickling filter. Furthermore, to ensure the normal growth of the microbes, nutrient solution is required to spray on the filler, during which a water film is easily formed on the surface of the filler and thus the water-insoluble substances are difficult to be utilized by the microbes. Thus, the selection and arrangement of the filler, the performance optimization, and the coupling bioreactor structure have been the focuses of the researchers in the field to improve the efficiency of the biotrickling filter.